Matte Finish Repair
Evaluate the finish on your wooden picture frame. Stand to one side of the frame and look for a glossy sheen. If your frame is fairly matte, you may be able to repair small scratches with a felt-tip scratch remover marker, available at home furnishing and hardware stores.
Repair a small scratch in a non-glossy finish with a felt-tip scratch remover marker. These markers are available in a wide variety of wood tones. Take your frame (or a color photo of your frame) with you to the hardware store when selecting your scratch remover marker. As long as the color is fairly close, the damage will not be noticeable after repair.
Dab the tip of the scratch remover marker into the scratch, taking care not to mark the undamaged surface of the frame. Allow the marker to dry overnight. If the scratch is noticeably less glossy than the surrounding finish, use padding lacquer to complete the repair.
Glossy Finish Repair
Repair a scratch in a glossy finish with padding lacquer and blending powders, available at specialty woodworking and furniture restoration shops. Select the color of blending powder closest to the wood color of your frame, or mix together different tones of blending powder to create your own blend to match.
Dissolve the blending powder in a small amount of padding lacquer solvent, and mix thoroughly. Add the solvent mixture to a small amount of padding lacquer, and mix thoroughly.
Paint the padding lacquer mixture into the scratch with the tip of a pointed artist's brush, and allow to dry overnight. If the area appears too light, mix a darker solution of padding lacquer and re-apply, and allow the re-application to dry overnight. If the repair area is too dull, apply a thin coat of clear padding lacquer to the area and allow to dry overnight.